Oceaniopteris Gasper & Salino, 2016

Gasper, André Luís De, Dittrich, Viníciusantonio De Oliveira, Smith, Alan R. & Salino, Alexandre, 2016, A classification for Blechnaceae (Polypodiales: Polypodiopsida): New genera, resurrected names, and combinations, Phytotaxa 275 (3), pp. 191-227 : 214

Oceaniopteris Gasper & Salino , gen. nov. — Type: Oceaniopteris gibba (Labill.) Gasper & Salino. Figs. 4F , 6C .

Diagnosis: Rhizomes short-creeping to erect with black, acuminate, acicular scales, except when aquatic ( O. francii ); fronds dimorphic to subdimorphic; proximal pinnae only slightly shorter than others, or greatly reduced (e.g., O. gibba ), veins free, furcate.

Plants terrestrial; rhizomes short-creeping to erect, non-stoloniferous, stout, sometimes trunk-like, clothed with black, acuminate, acicular, entire scales (except when aquatic, as O. francii ), or scales sometimes pectinate and broadened only at the very base, otherwise acicular for nearly their entire length (as in O. gibba ); fronds dimorphic to subdimorphic, or hemidimorphic (only distal pinnae fertile); stipes usually stout (but very narrow, 0.5 mm diam. in O. francii ), long or short, stramineous, brown, or blackish, with scales similar to those of rhizomes, fewer scales distally, scales sometimes deciduous, rarely with small hairs; blades concolorous, deltate to ovate (narrowly lanceolate in O. francii ), pinnate or pinnate-pinnatisect, slightly reduced proximally (greatly reduced in O. francii ), with pinnatifid apices; rachises glabrous or with sparse scales and hairs; buds absent; aerophores absent; pinnae adnate or petiolulate, linear to narrowly elliptic, entire to serrate-dentate; veins free, furcate, each ending in a clavate hydathode adaxially; sori linear, on both sides of costae, indusia entire (over-arching and covering sporangia at maturity in O. francii ); x = 32.

Species number, comments, etymology, and distribution:— About eight species, distributed in Malesia, Fiji, New Caledonia, and Australia. This genus has trunk-like rhizomes, sometimes more than 1 m tall, with the exception of O. francii , an aquatic plant. The rhizomes have black, acuminate, acicular scales, and the fronds are dimorphic to subdimorphic. Oceaniopteris is similar to Neoblechnum brasiliense , which occurs only in the Neotropics, and has glossy, acicular, curved, entire scales and monomorphic fronds. The name was coined for the exclusively Oceanian (in Oceania) distribution of all known species. It is closely related to Neoblechnum and Doodia (Gasper et al. in press).

Figures

FIGURE 4. General appearance of the genera of Blechnaceae subfamily Blechnoideae (G-S). A. Icarus filiformis (WELT P009478); B. Lomaria nuda (P01557820); C. Lomaridium fragile (MEXU 149093); D. Lomariocycas aurata (QCA7004842); E. Neoblechnum brasiliense (FURB06585); F. Oceaniopteris cartilaginea (P01630912). G. Parablechnum cordatum (FURB06639); H. Sadleria pallida (MEXU 956078); I. Struthiopteris spicant (P01658104). Vouchers are indicated by herbarium barcodes.

FIGURE 6. Habitat of Blechnaceae genera. A. Blechnum occidentale; B. Brainea insignis; C. Cleistoblechnum eburneum. D. Cranfillia vulcanica; E. Diploblechnum fraserii; F. Doodia caudata; G. Icarus filiformis; H. Lomaria spannagelii; I. Lomaridium acutum. Photos from: A. Luis Adriano Funez; B. Ralf Knapp; C. Ralf Knap; D. Julie F. Barcelona; E. Michael Sundue; F. Paulo Araújo; G. WELT herbarium; H. Vinícius A.O. Dittrich; I. Tiago João Cadorin. Reproduced with permission from the authors.